The Tomini of Indonesia occupy the northern Sulawesi peninsula from Donggala to Gorontalo. The name "Tomini" is both a geographic and linguistic designation. Geographically, Tomini is a thin strip of land which borders the western edge of Tomini Bay; linguistically, Tomini is a subgroup of western Central Sulawesi languages which include Toli-toli, Dondo, Bolano, Tinombo, Kasimbar, Dampelas and Ndau. Although linguistics formerly thought all Tomini languages were mutually intelligible and the different names merely referred to dialects, recent research has asserted that each group forms a separate language. Supposedly these multiple language originated from the area's many political-trading empires, which remained historically and culturally insulated from each other until Islam unified them in the sixteenth century.